Gridded Data Format
Please be advised! Once you click on the particular gridded
file you wish to obtain, it will open an anonymous ftp session
where you can download the file. The gridded files are gzipped
because of their size. When they are unzipped, each file is
about 3 megabytes in size. Users may feel free to utilize a viewer that
can translate the downloaded uncompressed gridded file format
into a comma-delimited ascii version:
Below is a description on how the read the file.
The gridded files of cyclone wind components have the following
A few lines giving the grid spacing in meters and the
latitude and longitude of the storm center. In mercator cartesian
coordinates the storm center is at (x,y)=(0,0)
Cartesian coordinates (meters) are then given for the grid
boundaries. First listed are the WEST TO EAST mercator X
coordinates which pass through the storm center at x=0. They
are listed in increasing order from WEST to EAST. The total
number of entries is given before the coordinate listing so that
the entire set of MERCATOR X COORDINATES can be read in at once.
Next the SOUTH TO NORTH mercator Y coordinates (meters) which
pass through the storm center at y=0 are listed. They are listed
in increasing order from SOUTH to NORTH. The total number of
entries is given before the coordinate listing so that the
entire set of MERCATOR Y COORDINATES can be read in at once.
The next listing is the EAST LONGITUDE COORDINATES of the
grid boundary followed by a listing of the NORTH LATITUDE
COORDINATES of the other two grid boundaries. Again, before the
actual coordinates are listed. an integer specifying how many
coordinate entries follow is given to facilitate reading them in
as a single array all at once.
Finally, the SURFACE WIND COMPONENTS (M/S) are listed as a
listing of complex numbers of the form (u,v). They should be
read in as a SINGLE COMPLEX ARRAY of two dimensions. The
dimensions of the array are given on a line preceeding the
actual component listing again so that the entire array can be
read in at once.
Return to H*Wind page.
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